One thing I appreciate when I travel to speak somewhere are the friendships I acquire. I'll tell you this right now that if I had to choose what to believe based on the warm reception I felt at the debate with Dinesh I would become a Catholic. They were all respectful and kind towards me. Kindness does wonders I think. One such friendship I gained was with Kenneth J. Howell, the Director, St. John’s Institute of Catholic Thought, who put the debate together. Among other books he is the author of God's Two Books: Copernican Cosmology and Biblical Interpretation in Early Modern Science. He also has an interesting story since he used to be a Protestant. Here's his challenge and our initial discussion below:
Dr. Howell:

I have a question I want pose to atheists to see how they would answer it. Those answering it will probably have to have some experience in philosophical reasoning (particularly philosophy of science).

Challenge: Knowledgeable atheists claim that the existence of God does not have any evidential basis. Sometimes this comes in a strong form, “There is no evidence that God exists,” or sometimes in a milder form, “The evidence for God’s existence is deficit.” The atheist’s challenge to the theist might be formulated, “Show me the evidence for God’s existence without assuming the correctness of your religion or theology.”

This raises the issue of how we human beings know the existence of any unobservable entity given that we do agree on the observable data. For the purpose of this exercise, I must ask all parties not to distinguish between theoretical entities in science like electrons which may be observable in principle and metaphysical entities like human personality which may never be observed, even in principle.

The theist might challenge the atheist as follows:

Show that electrons (or any other unobservable entity in science) exist without assuming the correctness of atomic theory.

I presume that the atheist would want to differentiate between these two cases, showing in effect that the evidence for God’s existence is deficit while the evidence for electrons (or any other unobservable in science) is well-founded. At a more general philosophical level, then, this tack assumes our ability to distinguish the postulation of unobservables that are well-founded from those that are not-well-founded. Such a tack requires answering the following questions:

Is it rational to believe in unobservables only in tandem with the theory in which those unobservables are postulated? That is, can I be justified in believing in electrons without atomic theory?

By what criteria in general do we know when an unobservable is justified?

Are unobservables in scientific theories theory-dependent or theory-independent? Or does it depend on the theory in question?

John:

Hi Kenneth,

Postulating the God hypothesis as a theory to explain the phenomena of existence is an entirely legitimate way to proceed. So I grant you this. And I grant you that it is rational to conclude God is the best explanation of the evidence. The criteria question is multifaceted and not easily specified. Not being as familiar with science as you are, I can only respond to the God hypothesis. Is that the best explanation of the evidence? There is Ockham’s razor, you know. Gregory Dawes in his book Theism and Explanation is heralded as one of the best atheist books of the last decade. I have an e-copy of it and am reading it now. I suggest you look into this book as I am doing for what looks like the answer to your challenge.

And what kind of evidence are we talking about? There is negative evidence based upon the God of the gaps, i.e., the unexplainable mysteries. When it comes to this kind of evidence I admit with Robert Lamar that this is an entirely legitimate way to proceed.

But the question becomes what method do you propose that is better than methodological naturalism to close these gaps? Barbara Forrest argues that “the relationship between methodological and philosophical naturalism, while not one of logical entailment, is the only reasonable metaphysical conclusion given (1) the demonstrated success of methodological naturalism, combined with (2) the massive amount of knowledge gained by it, (3) the lack of a method or epistemology for knowing the supernatural, and (4) the subsequent lack of evidence for the supernatural. The above factors together provide solid grounding for philosophical naturalism, while supernaturalism remains little more than a logical possibility."

Given that we accept and defend that which we prefer to be true we should not leap with faith beyond what the evidence calls us to accept. If the evidence leads us to think the God hypothesis has a 55% chance of being correct then we cannot leap with faith beyond that evidence to claim we know God exists. We can only claim what the evidence actually leads us to think, and therefore at best I should only give 55% of my life over to the God hypothesis, not 100% (granting this percentage).

When it comes to positive evidence, that is, evidence that God exists, there just doesn’t seem to be much at all. There is personal experience, but then religious experiences are claimed by almost every religious person and they disagree with each other about which god they experienced, so although it is considered by believers to be powerful personal evidence it really isn’t anything other than anecdotal evidence. What you have left then is historical evidence, which is really weak as evidence, as philosophers of history have repeatedly shown us. Almost anything can be rationally denied in history even if it happened.

Kenneth:

You didn't address the justification for believing in electrons in your message, what you did say was thought provoking. Let me give this stuff some thought.

Perhaps you can give me a quick answer to this:

Is it common among AAFs to believe that only one explanation is necessary? i.e. that if we explain the mechanisms of the natural world, as in science, we don't need anymore explanations, or better, explanatory levels?

As a multiplanar thinker, I have deep suspicions about reductive explanatory tendencies. Are reductive explanations necessary or common part in an AAF worldview?

John:

Reductive explanations? An interesting thought. You might want to give me more examples of what you mean in terms of physics. On one level a mechanistic explanation works but behind that is a supernatural one, you'd claim. That's the question, isn't it? And I grant this might be the case but I have no way of knowing that it is, you see. As I argued, once we allow supernatural explanations into our equations then any supernatural explanation will do.